Method of forming celluloid printing plates



F. C. GOLDENBAUMH METHOD OF FORMING CELLULOID PRINTING PLATES.

APPLICATION HLED AUG-3L 1920.

Patented July 111 19220 m Hiram 6.

ATTORNEY ANT came.

' FREDERICK Cl GOLDENBAUM, or KEArmm; NEW JERSEY, ASSIGNOR 'ro INTERNA- TIONAL PRINTING PLATE COMPANY, INC, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

METHOD OF FORMING CELLU'LOID PRINTING PLATES.

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To allwhomit may G0nb'6m,'

Be it known that I, FREDERICK C. GOLDEN- BAUM, a citizen of the United States, resid- Forming Celluloid Printing Plates, of which the following is a specification.

My invention relates generally to printing plates and more particularly to improvements 'in the method of forming celluloid plates described in the patent, to Ludwig 747,738, Dec. 22, 1913.

In manufacturing celulloid printing plates according to the method referred to, Ihave found that the use of unyielding material such as steel or other metal as a die member for forcing the celluloid into engagement withthe face of. the lead mold gives very imperfect results because of the failure of the rigid forcing die member to adapt itself to variations in the thickness of the celluloid. I have avoided this by making use of loose pads of felt arranged to directly receive and apply the pressure of the forcing die to the celluloid which was interposed between the felt pad and the operative face of the heated lead mold. This method,

.while largely overcoming the objectionable features arising out of the use of an unyielding. forcing die member, was still open to the objection that interstices in the surface of even the fine quality of felt employed would occasionally permit of the failure to press a minute portion of the celluloid into the face of the mold with a consequent loss of a corresponding microscopic detail in the finished plate.

I have discovered that I can overcome the objections referred to and, as a result, obtain celluloid printing plates in which the finest details of the design carried by the mold are faithfully reproduced in the celluloid. I accomplish this by placing between the felt pad and the thin sheet of celluloid on which the impression is to be made at second supplemental sheet of celluloid which serves to transmit from the felt pad to every portion of the'area of the sheet in contact with the mold a uniform pressure that forces the sheet into contact with every minute detfail of the design formed in the mold sur ace.

In the drawing the single diagrammatic Specification of Letters Patent.

Patented July Ill, 1922.

Application filed August 31, 1920. Serial No. 407,280.

view shown illustrates a preferred form of apparatus for carrying out the method embodying the present invention.

Referring to the drawing, there is shown at l the stationary bed plate of a suitable hydraulic press of which the member 2 represents the vertically reciprocable forcing member or die head. At 3 is shown a removable die plate which, together with the lead matrix or mold member 4, is heated in any suitable heating device, not shown, to a temperature such as will reduce to a desired condition of plasticity a sheet of celluloid 5 when the sheet is pressed against the upper surface of the lead plate 4 on which the design to be reproduced appears.

In order to 'avoid the use of the unyielding surface of the die head 2 with the celluloid and a resulting imperfect impression and possible rupture, and distortion. of the sheet, I make use of the felt cushion 6 which is placed in an intervening position between the die head 2 and the celluloid sheet, as has been already described.

A still more important feature of the invention resides in the placing of a supplemential sheet of celluloid 7 between the cushion 6 and the impression-receiving sheet 5. .The supplemental transfer or cushion sheet 7 serves to absorb the surface irregularities of the felt pad and to transmit uniformly to every portion of thesheet 5 the pressure exerted by the die head 2, with the result that every fine detail of the design on the face of the mold member 4 is accurately reproduced on the surface of the sheet 5.

The plate 5 is retained under pressure for a sufiicient time to permit the temperature of the die 3 and mold 4 engaged thereby to fall below the temperature of plasticity of the celluloid when, the celluloid plate 5 having become hardened into its permanent condition is removed and mounted on a suitable blockfor use as a printing element.

It will be noted that the various members of my pressure applying apparatus are wholly unattached from each other so that and over again for a great many plate forming operations. Y

1. That method 'of forming aprinting plate which consists in pressing a body of material rendered plastic by heat, between a mold heated to a temperature suflicient to render the material plastic, and a yieldable body of similar material. f

2. That method of forming a printing plate which consists in pressing a sheet of material rendered plasticby heat, together with a supplemental cushion sheet between a mold heated to a temperature sufiicient to render the material plastic, and a cushioning member.

3. That method of forming a printing plate which consists in pressing a sheet of celluloid between a'lead mold heated to a temperature suflicient to render the celluloidplastic, anda felt cushioning member. I

' ing member.

4. That method of forming'a printing plate which consists in pressing a .sheet of celluloid between a lead mold heated to a temperature suflicient to render the celluloid plastic, and a yieldable sheet of similar material.

5. That method of forming a printing plate which consists in pressing a sheet of celluloid together with a supplemental cushioning sheet of celluloid between a lead mold heated to a temperature sufiicient to render-the celluloid plastic, and a cushion- 6. That method of forming a printing plate which consists in pressing together a heated die plate, aheated lead mold, an impression receiving sheet of celluloid, a cushioning sheet of celulloid, and a felt pad arranged in the order named, in cooling and a dlsassembllng said parts, and 1n removing.

the impressed sheets from contact with said mold.

Signed at Arlington, in the county of Hudson, and State of New Jersey, this 28th day of July, 1920.

FREDERICK C. ,GOLDENBAUM. 

